European patent No 352286 relates to improvements in the separation of macromolecular solutes by a process known as electrophoretic separation, in particular fixed boundary electrophoretic separation. In fixed boundary electrophoresis, as is explained in more detail below in the description following the Brief Description of the Drawings, a semi-permeable membrane (hereinafter referred to as a separation membrane) acts to separate two streams of liquid carrying macromolecular solutes such as proteins, referred to as the upstream and the downstream. The streams pass between charged electrodes and at least one macromolecular solute migrates across the membrane from one stream to the other under the influence of the electric field. The apparatus also includes flow paths for buffer solution and further semi-permeable membranes, hereinafter referred to as restriction membranes, disposed between the electrodes and the separation membrane. The restriction membranes allow the passage of ions but not macromolecules.
The present invention relates to developments and improvements over the ideas and principals disclosed in EP 352286 and in particular to refinements and improvements to the apparatus to make the technology easier to use and operate.
In particular, it is one desired object of the present invention to provide an apparatus which is easier to fill, empty, clean and reassemble in contrast to existing apparatus such as that described above which tends to be formed substantially integrally with storage tanks, pumps, cooling apparatus and similar features making the apparatus expensive and difficult to handle and clean.
The lack of ease of use of the prior art apparatus is a serious disadvantage and tends to make separation of molecules by electrophoresis an unnecessarily complicated, tedious, time-consuming and expensive procedure.
Thus it is a further object of the present invention to provide an electrophoresis apparatus which is simpler and relatively quicker to operate than existing apparatus to set up and use.
A further problem associated with the prior art id the amount of "downtime" involved after the apparatus has been used and before it can be set up for a further separation. Electrophoresis apparatus is expensive and the downtime is consequently a serious cost disadvantage.
Thus it is a further object of the present invention to provide an apparatus whose downtime is reduced in comparison with prior art apparatus.
A yet further problem of existing electrophoresis apparatus relates to the size of the samples which are typically separated by such apparatus, the amount of sample to be separated can be very expensive, and consequently the smaller the sample which can be separated by the apparatus, the better.
It is a yet further object of the present invention to provide an apparatus which can be used to separate relatively small samples sizes.
Existing electrophoresis apparatus is also very bulky and can take up a large area of laboratory space.
It is a yet further object of the present invention to provide an apparatus which in its preferred embodiment can be relatively compact.
A further problem with existing electrophoresis apparatus is that it can require a relatively high current and voltage to operate.
It is a further object of the present invention to enable an electrophoresis apparatus which uses less power and hence is more economical and also causes less electrical heating to the sample being separated which can damage the sample.